WASHINGTON -- The list of 15 employees losing their jobs in the aftermath of General Motors' ignition switch crisis includes Mike Robinson, vice president of sustainability and global regulatory affairs, Bloomberg reported.

And two others who are no longer with the company include Gay Kent, general director of vehicle safety, and Carmen Benavides, director of field product investigations, two sources told Automotive News.

Robinson is the highest-ranking executive dismissed by the automaker as it investigates defective parts linked to 13 deaths, a person familiar with the matter told Bloomberg.

Robinson privately urged another GM employee to push back against the National Highway Traffic Safety Administration’s concerns that the automaker was responding too slowly to recalls, according to e-mails released by Congress in April.

A home phone number for Robinson couldn’t immediately be found for comment. A GM spokesman declined to make him available.

Kent's role

Kent, who in 2013 was named a “champion” for an internal investigation into crashes in which airbags did not deploy, and Benavides, who was GM’s day-to-day liaison with U.S. auto-safety regulators, are among the highest-ranking officials who were aware of the defect before the end of 2013, according to the report released on Thursday by independent investigator Anton Valukas.

GM has declined to comment on the identities of the 15 ousted employees. Benavides and Kent didn’t respond to online messages seeking comment. But their ouster signals GM CEO Mary Barra’s intention to cut through GM’s bureaucracy and act with a sense of urgency.

“While everyone had the responsibility to fix” the defect, Barra said at a town hall-type meeting with employees in suburban Detroit, “no one took responsibility.”

The identities of five of the 15 ousted GM employees are now known. Besides Kent and Benavides, they are Ray DeGiorgio, who approved the faulty switch and then fixed it without changing the part number; DeGiorgio’s supervisor, Gary Altman; and William Kemp, the lawyer who oversaw GM’s defense against lawsuits involving the switch.

Kent did not come off well in Valukas’ report, which says it took her team six months to move toward a recall after learning in April 2013 that engineer DeGiorgio had changed the faulty ignition switch and "misled his colleagues for years" about it.

The response to that information, the report says, "was to hire an expert.”

Kent, like the two previous champions, was brought in “to help resolve an unexplained pattern of airbag non-deployments in an expeditious manner,” the report says. “But they did not elevate the issue to their superiors, and the common thread was to hold more meetings and refer the matter to additional groups or committees.”

Benavides' role

Benavides’ signature, a fixture on GM’s filings with NHTSA, stopped appearing on the documents this year. The company confirmed in May that she had been reassigned.

Benavides was the recipient of a pointed July 23, 2013, e-mail from Frank Borris, director of NHTSA’s Office of Defects Investigation, or ODI, complaining about GM’s willingness to execute recalls. The e-mail, released as part of a U.S. House investigation, said GM was "slow to communicate, slow to act, and, at times, [required] additional effort of ODI that we do not feel is necessary with some of your peers."

Benavides forwarded the e-mail to several top executives, including Alicia Boler-Davis, senior vice president of global quality and customer experience; John Calabrese, vice president of global vehicle engineering; Gerald Johnson, vice president of North American manufacturing; and Robinson.

Robinson forwarded the message to Kent, saying it came “like a bolt out of the blue.”

"We worked way too hard to earn a reputation as the best,” Robinson wrote to Kent, “and we are not going to let this slide.”